Method of distilling petroleum mixtures



June 13, 1933. w. E. LUMMUS METHOD OF DISTILLING PETROLEUM MIXTURES Filed July 27, 1927 filo 612327 w rren a. wuss,

Patented June 13, 1933 UNITED STATES PATENTOFFICE or LYNN, mssncnusn'rrsjassrcnon TO THE LUMMUs M; rm, A conronarron OFDELAWABE mn'rnon or nIsrILLING rnrnonniim mx'runas 1 Application ma July 27,

1 present inventionrelates to a method and apparatus for distilling petroleum mixtures. I

The object of the invention is to produce 5 an efi'ective method and apparatus for dividing crude petroleum into a number. of different. commercial "products and the invention consists in the method: and apparatus for distilling petroleum mixtures hereinafter described and particularly defined in the claims. 1

The accompanying drawing illustrates diagrammatically a form of apparatus for working the method. v y y The .method of the. present inventionis described as follows; The presence of water and permanent gases in a petroleum mixture suchflas crude innvarying amounts and proportions is prejudicial to the certainty of success of operation of distillin such crude oil. Therefore it is preferred t at preparatory to the practice of the method upon crude.

petroleum, the oil be first degasified and dehydrated, and for this purpose the method of the Coubrough application filed March 4;

' begins to descend through the column and is subjected to the stripping action of a counter-current of steam rising through the column which, increasing the vapor tension,

releases lighter oils which vaporize and pass off through the vapor pipe 68 to a mediate point inthe column 62. The oils passing downward through the column are stripped to a predetermined initial boiling point in the presence of steam, which is the end point of the distillate effluent from the column 55. This column is a distilling and rectifying column having steam admission 1927. Serial no. 208,680.

pipe 66 atits bottom. In this column the vaporsare rectified and certain of the vapors are condensed as condensates and flow down- Ward through the column. A bottompart of the column has a stripping section 64 wherein any liquid condensates flowing down through the column are stripped of any oils havingfan initial boiling point below that of a predetermined minimum. Liquid condensates collect in thebottom of this column 62 and descend into the bottle 200 fromwhich a portion passes down through the pipe 74. and thence to thelook box 76 where they are drawn off as a product. Theliquid residue flowing down from the bottle 200 passes through a. cooler 201 where it is cooled on its way to the look box. A valve202 in the pipe 74 near the look box afi'ords means for regulating the amount of condensate delivered back to thetop of the column 55 by the reflux pipe 203. This reflux pipe delivers a reflux of condensate from the column 62 to the top. of the column 55 and tends to controlthe composition of the vapors eifiuent therefrom, y y

The vapors effluent from the column 62 pass through the vapor pipe 71 to a mediate point in the column 68 where distilling and rectifying operations are performed for the purpose of dividing the incoming vapors into different groups of oils. A portion of the vapor in the column 63 condenses there and such condensate is distilled in the presence of steam admitted through the pipe 67 at the bottom of the column. This stripping action takes place in the stripping section 65 of thiscolumn and any condensate finding its Way to the bottom of the column is drawn off and runs into the bottle 210 from which a portion flows through the pipe 7 5 and the cooler 211 to the look box 7 7 a valve 212 being provided in the pipe 75 to regulate the 7 bottle 220. Any small quantity of uncondensed distillate flowing rom the condenser 81 is permitted to escape through the bend in the top of the bottle 220. From the bottle 220 a pipe leads to the decanter 82 where the water and oil are separated, the oil passing into the bottle 221 and a portion of it being drawn ofl through the pipe 84 passing through the cooler 222 to the look box 85, a Valve 223 being provided in this pipe to regulate the flow of a portion of the condensate from the condenser through the reflux pipe 83 back to the top of the column 63 where it controls the composition of the vapors :ef-j

fluent therefrom.

It is to be observed that the oil mixture is first heated to form'a vapor distillate mixture. It is then allowed to vaporize and the lighter portions of it vaporize in column which may be referred to as the first column.- The temperature to which the oil is heated is the temperature of the initial boiling point of the residue desired'from the first column and consequently the end point of the various distillates desired to be removed from the oil. The vapors efliuent from this column pass into the second column. 62 where they are further rectified. The condensate refluxed from the second column to the top of the first, controls the end point of the efiuent vapors of any of the higher boiling oils which it is desired to remove fromthe products beyond. The stripping section 64 of the column 62 is employed to remove any lighter oils'in solutionin heavier. oils condensing in that column. These lighter oils pass upward through the column 62 and flow out therefrom to the third column 63 while the heavier oils condensing in the column-62 fiow downward and are collected as gas oil. A similar operation takes place in respect to the third column from which the liquid condensate is drawn as kerosene and the vapor distillate being condensed, is drawn off as 'gasolene. 1

"Having thus described the invention, what is claimed is:

1. The methodof dividing petroleum mixtures to form a plurality of products which consists in vaporizing low boiling components from the mixture to leave a residual product, passing the vapors into mediate points of a succession of distilling and rectifying zones, condensing the final vapors to obtain a light product, subjecting the vapors in each zone to counter-current with reflux liquids derived fromthe process, introducing steam into each zone below the point of admission of the vapors and in counter-current with all of the reflux liquid in each zone to vaporize low boiling components therefrom, withdrawing from each zone a portion of the reflux liquid treated in said zone as an intermediate prod- I uct, restricting the withdrawal of the liquid,

returning'the remainder directly as reflux int the adjacent earlier zone, and controlling the composition of the products by varying the rate of withdrawal of each such intermediate product to control the amount of reflux returned to said earlier zone.

2. The methodof dividing petroleum mixtures t form a plurality of products which consists in vaporizing low boiling components from the mixture in a .counterscurrent of steam to leave'a residual product, passing the vapors into a mediate point of a rectifying anddistilling zone, introducing into the top of said zone a reflux liquid derived from the process, intr oduc-i;ng steam into the bottom of said zone in counter-current to all of the reflux liquid'to remove low boiling components therefrom, withdrawing a portion of the reflux liquid thus treated as an intermediate product, restricting the withdrawal of said product, returning the remainder directly as reflux in counter-current to the vapors vaporized from the'original mixture, and controlling the constitution of said intermediate product by varying the rate of the withdrawal of said product, thereby controlling the rate of return of reflux liquid. 1

3. In a method of dividing petroleum mixtures, the steps which consist in passing vapors through a rectifying zone and then into a mediate point ofa rectifying and distilling zone, subjecting the vapors to countercurrent contact with reflux liquid admitted at the top of the rectifying and distilling zone, introducing steam into the rectifying and dis tilling zone at the bottom to pass in countercurrent to all of the reflux liquid and to vaporize low boilin components therefrom, withdrawing from t 1e bottom of the rectifying and distilling zone a portion of the reflux liquid thus treated as an intermediate product, restricting the withdrawal of said product, returning the remainder directly as reflux into the rectifying zone, and varying the rate of withdrawal of said intermediate product to control the amount of reflux returned to said rectifying zone to control the composition of the product.

4. Apparatus for dividing petroleum mixtures into a plurality of products having, in combination, a vaporizing section, a rectifying and distilling section, means for conductingvapors from the vaporizing section to a mediate point of the rectifying and distilling section, means i for admitting reflux into counter-current with the vapors in the rectifying and distilling section, means for introducing steam into the bottom of the rectifying and distilling section to pass in countercurrent with all of the reflux and to remove low boiling components therefrom, a drawoff pipe for removing a portion of the reflux liquid as an intermediate product, a connection for returning the remainder of the reflux directly into the vaporizing section, and a valve in the draw-off pipe for restricting the rate of withdrawal of the product to control the rate of return of reflux to the vaporizing section and thereby to control the composition of the product.

In testimony whereof I have signed my name to this specification.

WALTER E. LUMMUS. 

